“His task was twofold: practical and theoretical. He preached the gospel of free and universal grace from Damascus to Rome, and secured its triumph in the Roman empire, which means the civilized world of that age. At the same time he built up the church from within by the exposition and defence of the gospel in his Epistles. He descended to the humblest details of ecclesiastical administration and discipline, and mounted to the sublimest heights of theological speculation.” Philip Schaff, History of the Christian Church, vol. 1, p. 318